I have three 175 watt solar panels on the back of my yacht that were installed by the previous owners in 2010. Would it be any benefit of improved performance to replace them with the same size new panels? Has there been much improvement to performance in 7 years

If you calculate the ROI of your replacement, you should divide the costs by the EXTRA watts you get. It will show you an extraordinary cost per watt. Unless you absolutely need more watts this solution does not seem practical.
My guess is that a (flexible) additional panel will be much more cost effective.

You would end up with many more watts in the same size. Depends on your battery bank whether it would be worth it.

can you explain this please, most panels still seem to be in the 16-20% efficiency range with some of the top Sun Power panels at 22%.

AK, what sort of solar panel controller are you using? there may be some improvements there if its a PWM and you switch to MPPT. The price of MPPT controllers like panels has dropped dramatically over the last few years.

can you explain this please, most panels still seem to be in the 16-20% efficiency range with some of the top Sun Power panels at 22%.

AK, what sort of solar panel controller are you using? there may be some improvements there if its a PWM and you switch to MPPT. The price of MPPT controllers like panels has dropped dramatically over the last few years.

Pete

+1 on the Sun Power panels. I'm using the 345W ones, and they have exceeded rated output on occasion, even mounted flat. I was very surprised.

But, any shading (mast, rigging) is detrimental to performance. Connect panels in parallel, and definitely use a quality MPPT controller.

Will it be cost-effective upgrading? Probably not, but if you really need the extra output then it might still be worth doing.

Question to all, how are you calculating your efficiency % ie time span, location of boat etc. thanks.

I think it comes from the percentage of panel output from a maximum available power of 300 watts per hr a sq ft
noting as you go further from the tropics 'out of season' the sun angle is more oblique, so less power

In the next 2 years, new solar panels will becomes available using Perovskite structure compound.
This will add potentially another 5% to 7% efficiency to current solar cells and dramatically lower cost.

Location: Currently on the boat, somewhere on the ocean, living the dream

Boat: Morgan 461 S/Y Flying Pig

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Re: Have solar panels technology improved in the last seven years

On the other hand, I just swapped my 3 Kyocera total 370w panels and replaced with 2x Sunpower 360w panels taking one extra inch on all dimensions (2" longer and wider), essentially the same footprint.

That was two months ago. I previously ran our Honda about every other day, and chronically undercharged my batteries.

I have yet to run my Honda, and my Balmar Smart monitor has shown a full charge on all but a few days, when it was in the upper 90s.

It was literally life changing. I had about $2k in the panels and mods to my existing frame. It was worth much more to our lifestyle.

YMMV.

Efficiency is a measure of how many watts will be derived from the same area, such as a square meter. 22% efficient panels will generate half again the watts from the same space as 15% efficient panels, e.g.

It could be just that the sun is moving a bit far north from where I am at the moment that's put me on edge. I have a blue sky solar boost and never found any problems with charging the batteries in the middle of summer. Perhaps when I get to the tropics it should be better

I think it comes from the percentage of panel output from a maximum available power of 3100 watts per hr a sq ft
noting as you go further from the tropics 'out of season' the sun angle is more oblique, so less power